This invention relates to a machine for crimping the socket of a fitting onto a hose end by the radial contraction of a segmented die assembly and more particularly to improvements in the segmented dies and assembly whereby use of the machine is facilitated. This apparatus is particularly suited for makeup of flexible hose assemblies of various sizes at a field location. In this regard it is desirable to have a machine which may be readily converted from one size to another for the construction of fluid pressure assemblies of different flow and pressure capacities, which machine performs the crimping of the fitting onto the hose end in an expedient and highly reliable manner. It is also desirable that the machine be designed to reduce the possibility of errors or malfunctions in the hose assembly due to the selection of improper components for a particular size or due to errors in the operation of the machine. Still further it is desired that the machine be versatile so as to accommodate not only the straight end fitting which may not require more than a partial operating cycle of the machine but also that of the bent hose end fitting which may require the full operating cycle and partial disassembly of the machine in order to place the components in position to perform the crimping action.
Field crimping devices are well established in the prior art for rapidly, economically and consistently making quality hose assemblies. They are capable of achieving high hose assembly standards comparable to factory constructed assemblies. Their ready availability, however, necessitates design and operating characteristics which provide minimal chance for error in makeup of hose assemblies.
One group of prior art devices are those series of machines disclosed in U.S. Pat. Nos. 3,720,088, 3,742,754, 3,750,452 and 3,851,514. This type of equipment relates to bottom-loading crimper devices, that is machinery in which the hose end, with hose fitting to be attached, is presented to the crimping machine from a position beneath the machine. This has the advantage that the components and most of the sequence of action during crimping are viewable and accessible by the operator of the machine, and importantly, that relatively heavy and bulky hose assemblies may be supported on the floor with only one end presented to the machine. In many instances the hose assembly may be held in location by the operator with a single hand leaving the other free for operation of fluid valves and the like. In equipment of this type a hydraulic cylinder situated generally over the crimping stage produces a linearly directed force upon a radially contractible die assembly which is received in the tapered bore of a base plate or other reaction body member opposing the force of the cylinder. Linear movement of the die assembly into the tapered bore causes a camming or wedging action upon individual segments collectively forming the die assembly, to cause movement of the segments in a radially inward direction such that an inner cylindrical surface thereof receiving the socket of the hose fitting is reduced in diameter, thereby effecting the crimping action.
The machinery exemplified in the above-identified patents is characterized in particular in that the preferred collet assembly consists of a pair of collet segment halves which may be placed in position in the tapered bore with the inner cylindrical surface thereof in engagement with the collar of the hose fitting. The hose and fitting may be raised or shifted somewhat by the operator to settle the die segment halves into a matching configuration in the machine with the segment halves then being retained therein primarily by the force of gravity but also assisted to some extent by the weight of a spacer plate which is positioned thereover. The spacer plate is designed primarily to spread the force of the hydraulic ram and assure even movement of both halves of the die collet but serves as well as to limit the linear movement of the hydraulic ram and thus the radial contraction of the individual collet segments. The preferred form of die collet arrangement of these prior art devices is shown in detail in U.S. Pat. No. 3,750,452 wherein it is seen that elastomeric material is disposed between adjacent die segments in a split collet arrangement. The elastomeric material retains each of the die segments in each half of the collet and provides a spacing of the collet halves once they are placed in the tapered bore, preparatory to the crimping operation. The half collet arrangement is particularly advantageous in providing ease of loading and preparation of the machine and a facility for clearance of obstructions, as for example, those encountered when crimping bent hose ends.
Still further forms of the same line of equipment are shown in U.S. Pat. Nos. 4,034,592 and 4,034,593 where in similar crimping machines there are described improvements primarily in the support of the collet halves to facilitate the locating of same in the tapered die cavity automatically in each cycle of the crimping operation. These improvements in the placement of the collet halves free the operator for the functions of placement of the hose assembly in location, and for operation of fluid valves and the like and results in a speeding of the operating cycle of the machine.
Still another prior art approach is shown in U.S. Pat. No. 3,335,594, this being a top loading form of crimping machine wherein the preassembled hose with end fitting thereon is inserted from the top of the machine, to be acted upon in the crimping operation by the similar components of a linearly acting hydraulic ram and a plural die segment assembly operative to effect radial crimping by cooperation with the sides of a tapered cavity upon axial movement developed by the hydraulic ram. In this crimping device the die segments are separate and supported in the radial slots of a common die carrier which positions the die segments in a tapered die cavity. The necessary relative movement therebetween is effected by the upward movement of the block containing the die cavity under the urging of the hydraulic ram. Bent hose ends are accommodated as well in this form of structure, being limited primarily by the size of the throat of the die segment support member to which diameter the die segments can be retracted. In fact, in this machine the die segments can be fully removed from the support member. Final crimp diameter is determined by a visual gage device which must be judged by the operator to manually terminate the application of hydraulic force to the actuating ram.
In this form of device, different final crimp diameters may be achieved by alteration of the final stop position of the linearly acting pusher mounted on the piston. However, in any such machine the range is limited and it is necessary to substitute different die segments for various size ranges. It is necessary to assure that compatible die segments are being utilized to perform the crimping operation in order to obtain satisfactory connection between the end fitting and the hose.
This problem has been recognized in the past and one solution thereto is disclosed in U.S. Pat. No. 4,071,936 wherein each of the die segments in the die segment assembly is joined to two adjacent die segments by means of intermediate spring members such that the segments are always retained in the proper assembly. The limitation on devices of this type however is that only a certain expanded inside diameter of the die segment assembly can be attained dependent upon the resiliency of the intermediate springs and the size of the segments. A further detriment is that the entire assembly must be disposed over a bent hose end by stretching the unit and sliding the assembly over the hose end. To achieve expansion of the assembly and to support same during this maneuver it is necessary that the operator use both hands since die segment assemblies typically weigh on the order of upwards of five to ten pounds. It is apparent that some assistance would be required in holding the hose assembly in a prepartory position and in positioning and aligning the die segment members in this manner.